Safety device with collapsible housing and trigger activation

Abstract

Drug delivery safety devices having trigger activation systems activated by pressure against the skin of a patient and which automatically shield the needle after withdrawing the needle from the skin of the patient.

What is claimed is: 
     
       1. A drug delivery safety device comprising:
 a needle hub including a cannula having a distal tip; 
 at least two flexible arms adjacent to the needle cannula connecting a trigger housing at a distal end of the cannula to the needle hub, wherein the trigger housing has an aperture exposing the distal tip of the cannula; 
 a trigger mechanism within the trigger housing comprising a spring connecting the trigger housing to the flexible arms and a double leaf spring lock clip comprising an opening aligned with the distal opening of the trigger housing, a first leaf removably engaging the flexible arms and a second leaf engaging the trigger housing, the second leaf including a distal needle tip cover which is in contact with the needle cannula inside the trigger housing, out of alignment with the apertures of the trigger housing and the lock clip; 
 wherein a proximally-directed force applied to the trigger housing compresses the spring, moves the trigger housing proximally and disengages the first leaf of the lock clip from the flexible arms; and 
 wherein a subsequent decrease in the proximal force applied to the trigger housing decompresses the spring and moves the lock clip in a distal direction such that the needle tip cover of the second leaf of the lock clip disengages from the needle cannula and covers the distal tip of the cannula. 
 
     
     
       2. The drug delivery safety device of  claim 1 , which is attached to a syringe via the needle hub. 
     
     
       3. The drug delivery safety device of  claim 1 , wherein the at least two flexible arms are two flexible arms. 
     
     
       4. The drug delivery safety device of  claim 1 , wherein the spring is a spring coil or a leaf spring. 
     
     
       5. The drug delivery safety device of  claim 1 , further comprising an end-cap connecting the at least two flexible arms and wherein the trigger housing fits over the end-cap. 
     
     
       6. The drug delivery safety device of  claim 5 , wherein the first leaf of the lock clip removably engages the end-cap. 
     
     
       7. The drug delivery safety device of  claim 1 , further comprising a removable anti-triggering cap which fits over the trigger housing and prevents triggering of the trigger mechanism, the cap comprising an interior rib which engages the lock clip and prevents disengagement of the first portion of the lock clip upon application of proximal force. 
     
     
       8. The drug delivery safety device of  claim 1 , further comprising a bracket and a pull-pin, the bracket engaging the drug delivery safety device on either side of the trigger housing to constrain movement of the trigger housing, wherein the pull-pin facilitates removal of the bracket to permit movement of the trigger housing.